Cannot export chart in Calc as pdf

I have tried both in LibreOffice 6.4 under Linux Mint and LibreOffice 7.0 under Windows10. When I RMB clic on a chart in Calc and select > Export as image > PDF, it does not work. EPS and PNG formats do work properly, the PDF file has 0 bytes.

There is a bug report: fdo#111392


Try this. Select the chart. Then from menu → File->Export as PDF. Make sure Range has Selection/Selected sheets selected.

See related answer at Export as PDF with a 2-chart selection?